This invention pertains to the game of croquet, a game played out of doors on a course usually laid out on grass lawns. The equipment needed to play croquet, called a “croquet set”, consists of balls, striking mallets, wickets, and stakes. Wickets are in the general shape of an inverted “U”, the two legs of which are called stanchions. The two stanchions are impaled in the ground forming an arch through which a ball may pass. Stakes delineate various points of play within the course. The balls, precisely driven with mallets, are aimed at and must pass through wickets, with the game's objective being to traverse the course using fewer mallet strikes than opponents. The game of croquet traditionally has been played under daylight conditions so that players could see the wickets for the purpose of aiming shots and observing the passage of balls through wickets. However, croquet is often played as a form of entertainment under social party conditions. Such play, termed “yard croquet”, uses a home's yard area to layout conventional or irregular wicket courses conforming to available space. Yard croquet is frequently played under poor lighting conditions since social events typically extend into the evening. Diminishing daylight often curtails croquet play, since yard party lighting conditions are usually inadequate for seeing wicket positions or the passage of balls through wickets. This problem is exacerbated by wickets' being commonly fabricated from wire, making them difficult to see and determine if a ball has in fact passed through, or merely close beside, the wicket. Poorly illuminated wickets also present a tripping hazard for those walking on the course.
Casual attempts have been made to illuminate wickets. An example of this is the use of party lighting, such as strings of colored lights, to provide area lighting. This generally fails to clearly expose position or orientation of all the wire wickets as it is difficult to sufficiently illuminate an entire course in this fashion, especially if it meanders around corners of houses and garden areas, etc. Wide area lighting of sufficient brightness to clearly illuminate wire wickets at a distance is usually too bright to be aesthetically appealing for a night time social event. Another approach is to illuminate wickets by placing a candle in a paper sack near each wicket. This is unsatisfactory because the resulting diffuse illumination does not reveal a wicket so as to allow a distant player to see its exact center or orientation as needed to aim a ball through the wicket; furthermore, it does not clearly reveal the passage of a ball through a wicket. In addition, the candle and sack are subject to being struck by a ball, upsetting the sack, and possibly creating a fire hazard.
In order to facilitate and popularize night croquet to new levels, what would be desirable, but is missing, is a form of wicket lighting that:                1. illuminates wicket position and orientation from a distance,        2. clearly enables players to see a ball's passage through a wicket,        3. provides an aim point for players attempting a wicket shot from a distance,        4. is convenient to use and universally attaches to any style of preinstalled croquet wicket,        5. does not require the consumer to replace any existing croquet set components,        6. does not detract from darkness adaptation of the eye,        7. tolerates impact abuse from ball or mallet strikes,        8. is portable with self-contained power, requiring no external power source on the croquet course,        9. provides a low cost of operation,        10. consists of components that will not wear out quickly, providing a long useful life,        11. does not present hazards, and is tolerant of outdoor weather conditions, and        12. does not detract from social party ambiance, and ideally, even adds an element of festivity to the croquet course and party ambiance.        
Prior art has been discovered that attempts to fulfill at least some of the needs listed above. All such attempts that I am aware of are discussed below.
In U.S. Pat. No. 280,807 to Farley (1883), claim is made to illuminate all of the individual components of a croquet set by means of an unspecified luminous type paint. This includes mallets, balls, and stakes, as well as the wickets. Such a technique has many drawbacks, all related to the use of luminous paint. Modern luminous paints are of three types; (a) those that must be energized by exposure to light prior to use, (b) those that derive illumination from the admixture of radioactive substances, and, (c) those that fluoresce under illumination by external ultraviolet light. All of these paints are unable to provide area illumination other than at the actual surface to which the paint is applied. A painted item provides light that can be seen at a distance, but not light strong enough to illuminate surrounding areas. This weakness is particularly troublesome in the case of wickets. Wickets are commonly made of wire, presenting very little luminous surface to provide secondary illumination onto surrounding areas. Thus, at best, luminous paint will only suffice to mark the location and orientation of a wicket, and will do little to illuminate the playing surface under or around the wicket to reveal the passage of a ball through a wicket. My invention provides this missing attribute. Listed below are other drawbacks specific to each of the three types of luminous paints as they might apply to U.S. Pat. No. 280,807; alternatively, I present the attribute of my invention that would resolve each drawback.                a. Luminous paints energized by pre-exposure suffer from low luminosity for this application. Furthermore the amount of illumination deteriorates rapidly with time, so that only limited use is possible before the paint must be re-energized by exposure to light. It is questionable whether the duration of useful illumination would be long enough for a typical game of croquet. My invention provides a steady bright source of illumination for any length of croquet session.        b. Luminous paints that derive their luminosity from admixture with a radioactive substance suffer from low luminosity for the application of illuminating croquet play, and also may pose toxic hazards. Such paints are expensive and would likely be prohibitive to use in the quantities required for a consumer croquet set. My invention is a non-hazardous device of reasonable cost.        c. Luminous paints deriving their luminosity from incident ultraviolet light require that all parts of a yard croquet course be illuminated by ultraviolet lighting. This requires conventional power on the course, as well as a set up of wide area ultraviolet lighting, all of which present inconveniences. My invention contains its own power source and can be conveniently attached to wickets where ever they may be located, thus requiring no special logistic support for their use.It is likely because of these drawbacks that products based on the claims of U.S. Pat. No. 280,807 are not being marketed.        
In U.S. Pat. No. 5,370,390 to Swanson (1994), the claims indicate construction of an entire new croquet set, rather than utilizing existing equipment; this includes new mallets, balls, and stakes, as well as new wickets. Chemical light sticks are integrated into each item of the croquet set so as to allow replacement of depleted light sticks with freshly activated light sticks as needed. Such a technique has many drawbacks related to the use of light sticks as well as other factors; each drawback is listed below along with the respective superior attribute that my invention would provide:                a. In proposing to solve the problem of playing croquet under low illumination conditions, this prior art claims an entirely new croquet set design replacing conventional croquet set elements. This forces users to replace existing croquet sets to enjoy night croquet. My invention does not require any replacement of a consumer's existing croquet equipment. The lighting device claimed in my invention is additive to existing croquets sets, and is neither a mallet, a ball, a stake nor a wicket. Consumers adopting my lighting solution are saved the expense of duplicating existing croquet components.        b. The production of a completely new croquet set design, indicated in this prior art, requires a manufacturing facility to fabricate the many and varied elements of this new croquet set design. On the other hand, the device of my invention is simple to fabricate, requiring manufacture of a single item that is attached to the consumers' existing croquet wickets.        c. Light sticks produce diffuse light, rather than a concentrated intense beam of light. A focused beam is needed on the area directly under the wicket to unambiguously reveal the passage of a ball through the wicket. The device of my patent claim provides this essential feature to the play of croquet.        d. Activation of a light stick initiates a chemical process that cannot be stopped, and it steadily subsides with time over a number of hours until it ceases to provide useful illumination. A light stick will provide only one evening of play before needing replacement. Comparing the cost of light sticks to batteries reveals that to illuminate wickets for an evening of croquet would cost at least 40 times more using light sticks than using my battery operated invention. Thus my invention provides a far lower operating cost than the light stick approach.        e. There are two forms of abuse suffered by croquet wickets, (a) the force or impact required to install a wicket into the playing surface, and, (b) ill-directed mallet and ball strikes during play. Installation abuse can be substantial when the playing surface is hard ground; the thicker the wicket stanchion, the larger the force required to embed the wicket in the ground. If incorporated into wicket stanchions, light sticks, by virtue of their diameter, dictate a significant stanchion diameter. This, in combination with the suggested utilization of plastics for wicket construction could eventuate in wicket installation damage. Alternative embodiments propose a complex dual-thickness stanchion presenting a thinner section impaled in the ground to minimize installation loads; but this implies a more costly wicket. On the other hand, the device claimed in my patent simply attaches to a preinstalled wicket, thus eliminating installation abuse. Furthermore, my device design provides high tolerance to impacts anticipated in the croquet play environment.It is likely because of these drawbacks that products based on the claims of U.S. Pat. No. 5,370,390 are not being marketed.        
In conclusion, as far as I am aware, until the submission of my utility patent application, UNIVERSAL CROQUET WICKET LIGHTING UNIT, no solution has existed that successfully addresses all of the needs for illuminating croquet wickets for play under conditions of low lighting.